“That said, we do said we do think there is room for improvement in the licensing regime and we are conducting a review of our licensing arrangements at the moment, with a view to strengthening our requirements to raise standards in a couple of areas, particularly around customer service and financial resilience,” she said.

Consultation is under way and new rules start to be introduced in April.

One of the areas that would be looked at, she said, was the “readiness [of firms] to weather the challenges in this market”, particularly when wholesale prices of energy go up.

She defended Ofgem’s approach, saying there were now 60 energy suppliers, compared with a dozen or so a few years ago, to take on the Big Six suppliers.

The prices offered by the Big Six – British Gas, EDF Energy, E.On, Npower, Scottish Power and SSE – have clustered around the cap. Ms Stark said it was early days for the cap, which only came into force at the start of the year.

“I think the prices at which the Big Six are clustering now are lower than they otherwise would have been, so it’s win in that sense,” she said.

And, she added, there were better deals on the market for customers who wanted to shop around.